fix: Export exportTSInSecs field in TSDB identifier to make sure correct gap calculation

[honganan]

What this PR does / why we need it:

Which issue(s) this PR fixes:
Fixes #13115

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
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[chaudum]

@honganan Could you explain why making the field exported would change any of the logic and fix anything?

[honganan]

@honganan Could you explain why making the field exported would change any of the logic and fix anything?

@chaudum
In summary, the Meta(now in loki/pkg/storage/stores/shipper/bloomshipper/client.go) structure contains a Sources []tsdb.SingleTenantTSDBIdentifier field, and within tsdb.SingleTenantTSDBIdentifier, there is an exportTSInSecs field. When Meta is serialized and written to OSS storage, the exportTSInSecs field is being set to its default value, false, which is not the expected behavior. It should retain its actual value; otherwise, this will lead to issues during subsequent gap calculations.

loki/pkg/storage/stores/shipper/bloomshipper/client.go

Line 104 in b7fe6bf

Sources []tsdb.SingleTenantTSDBIdentifier

[chaudum]

@honganan Can you add a test case to assert that SingleTenantTSDBIdentifier.Name() is equal before and after a json serialisation roundtrip (json.Marshal + json.Unmarshal).

[honganan]

@honganan Can you add a test case to assert that SingleTenantTSDBIdentifier.Name() is equal before and after a json serialisation roundtrip (json.Marshal + json.Unmarshal).

Ok, Added it.